https://www.nowcoder.com/practice/7298353c24cc42e3bd5f0e0bd3d1d759
/**
* struct TreeNode {
* int val;
* struct TreeNode *left;
* struct TreeNode *right;
* };
*/
class Solution {
public:
/**
*
* @param t1 TreeNode类
* @param t2 TreeNode类
* @return TreeNode类
*/
TreeNode *mergeTrees(TreeNode *t1, TreeNode *t2) {
// 若存在一棵树为空 则返回另一棵树
if (!t1)
return t2;
if (!t2)
return t1;
// 两棵树都不为空
t1->val = t1->val + t2->val;
// 递归合并左右孩子 将结果存放在t1
t1->left = mergeTrees(t1->left, t2->left);
t1->right = mergeTrees(t1->right, t2->right);
return t1;
}
};